Hi, sorry to hear you have rats. I used to be quite tolerant of rats until they killed one of my ducks and also spread disease through a group of ducklings I had. The odd shy rat isn’t an issue, but if they are bold, adult, breeding and have found a good food source of duck food then I would definitely get rid of them. Firstly you need to rat proof the goose with fine chicken wire. Then remove the food source by only feeding in rat free secure areas (I feed floating waterfowl pellets during the day and wheat under water with pellets at night (with water available of course). Next get a humane rat trap with a bait of whatever they have been eating (duck food?) give them a few nights to get used to the trap (rats are very wary) then either relocate or dispatch anythat you catch. You can catch up to 4 young ones at one time with the traps. Legally you can’t relocate them but lots of people do. Make sure it’s well away from human dwellings. Dense woodland or open fields are good then the owls can benefit from them. Absolutely don’t use poison. Good luck!